Inclined Plane and sliding block

1. The problem statement, all variables and given/known data
The velocity of a 2.10 kg block sliding down a frictionless inclined plane is found to be 1.13 m/s. 1.00 s later, it has a velocity of 4.13 m/s. What is the angle of the plane with respect to the horizontal?

2. The attempt at a solution
I drew a diagram and everything...but I have never had to solve for an angle so I am not sure what formula to even start with.

I drew a diagram having the block sliding down the incline toward the origin and on the x-axis and I split the Normal into x and y components, can I do that? The only other force I have put on the block is the weight force. Is that right?